We have released TapExpense 2.2.1 last week and it's available on the App Store now. This version fixes a serious crashing bug in the Report tab when either of the two cases occurred:
None of the above cases occurred very often. We had received some user reports on the bug, but didn't have enough information to pursue further (and many who reported have reset their database or reinstalled the app to keep it working). We were very fortunate, and I'm really grateful, that many users were willing to help us with the debugging—which involves trying a number of ad hoc distributed fixes and sending us crash logs. None of those was trivial matter, and we have learned a lot from the debugging process. I apologize for all the inconveniences caused by this oversight on our part.
Upgrade is highly recommended for everyone.
At the mean time, TapExpense Lite 2.2.1 is being reviewed by Apple. If everything goes well it should be available on the App Store soon, too.
Thanks again to everyone who has helped us!